Electronic devices, such as computers and automotive components, include radiators, such as a heat sink, with which heat generated in a heating element, such as a semiconductor element or a mechanical component, is dissipated. A thermally conductive sheet may be interposed between the heating element and the radiator in order to increase the efficiency with which the heat is transferred to the radiator. An example of the thermally conductive sheet is disclosed in Japanese Unexamined Patent Application Publication No. 2012-038763 (PTL 1), which is a thermally conductive sheet filled with scaly graphite particles oriented in a specific direction which serve as thermally conductive materials.
It has not been possible to use the thermally conductive sheets including the oriented graphite particles in applications that require an insulating property although such thermally conductive sheets have a high thermal conductivity in the thickness direction, because graphite is electrically conductive. In order to address the above issues, WO2008/053843 (PTL 2) discloses a thermally conductive sheet formed by stacking an insulating resin film on a surface of a thermally conductive sheet filled with scaly graphite particles orientated in a specific direction which serve as thermally conductive materials.